Samsung released a download to fix the problem. I've tested it on Windows 8. Hopefully it works for Windows 8.1 as well.
My NP940X3G Is Displaying Yellow Incorrectly, How Can I Fix This? : Laptops | Samsung
I've been disabling the graphics driver before shutdown/restart and enabling the graphics driver after I login. This is inconvenient but I found it does make the screen colour ok when running on battery.
The steps below show how to do this
Included are two bat files, each can be run to either...
I think closing the lid to put it into sleep mode is not what you want to do. It does keep the colour but some battery is used during sleep mode.
Hmm..I doubt it's possible to trick it into thinking it's plugged in. Maybe an external battery pack would work. I haven't tried it before but I...
Laptops require a suitable graphics driver for the brightness controls to work. It would be best to use the driver from Samsung to ensure the best compatibility. I thought I was only one with this problem until I found your post.
I have the same laptop (Samsung ATIV Book 9 Plus) but I ordered from Amazon UK. I think the darker colour is related to power saving but I can't find where to disable it. It's definitely nothing to do with the screen brightness. Playing with the settings in the Intel HD Graphics Control Panel...